The simplest way to compile a program is to use the "backticks"
feature of the shell. If you enclose a command in backticks
(not single quotes), then its output will be
substituted into the command line before execution. So to compile
a GTK+ Hello, World, you would type the following:

Deprecated GTK+ functions are annotated to make the compiler
emit warnings when they are used (e.g. with gcc, you need to use
the -Wdeprecated-declarations option). If these warnings are
problematic, they can be turned off by defining the preprocessor
symbol GDK_DISABLE_DEPRECATION_WARNINGS by using the commandline
option -DGDK_DISABLE_DEPRECATION_WARNINGS

GTK+ deprecation annotations are versioned; by defining the
macros GDK_VERSION_MIN_REQUIRED and GDK_VERSION_MAX_ALLOWED,
you can specify the range of GTK+ versions whose API you want
to use. APIs that were deprecated before or introduced after
this range will trigger compiler warnings.

Here is how you would compile hello.c if you want to allow it
to use symbols that were not deprecated in 3.2:

The older deprecation mechanism of hiding deprecated interfaces
entirely from the compiler by using the preprocessor symbol
GTK_DISABLE_DEPRECATED is still used for deprecated macros,
enumeration values, etc. To detect uses of these in your code,
use the commandline option -DGTK_DISABLE_DEPRECATED.
There are similar symbols GDK_DISABLE_DEPRECATED,
GDK_PIXBUF_DISABLE_DEPRECATED and G_DISABLE_DEPRECATED for GDK, GdkPixbuf and
GLib.

Similarly, if you want to make sure that your program doesn't use any
functions which may be problematic in a multidevice setting, you can
define the preprocessor symbol GDK_MULTIDEVICE_SAFE by using the command
line option -DGTK_MULTIDEVICE_SAFE=1.

Useful autotools macros

GTK+ provides various macros for easily checking version and backends
supported. The macros are

This macro should be used to check that GTK+ is installed
and available for compilation. The four arguments are optional, and
they are: minimum-version, the minimum version
of GTK+ required for compilation; if-found, the
action to perform if a valid version of GTK+ has been found;
if-not-found, the action to perform if a valid
version of GTK+ has not been found; modules, a
list of modules to be checked along with GTK+.